Cell Surface Antigens Research Articles

Abstract 6757: The anti-tumor efficacy of Th1-specific TROP2 vaccine (AST-07X) in a triple-negative breast cancer murine model

Abstract Background: The trophoblast cell-surface antigen 2 (TROP2) is associated with enhanced tumor proliferation and poor prognosis in breast cancer. TROP2 overexpresses on various epithelial cancer cell surfaces, and is commonly found in prostate, colon, pancreas, lung, and breast cancer. Therefore, anticancer strategy targeting TROP2 may be a potential treatment option for patients with metastatic triple-negative breast cancer (TNBC). Sacituzumab govitecan, a Trop-2-directed antibody drug conjugate (ADC), has shown significant benefits associated with progression-free and overall survival compared to standard chemotherapy for treating metastatic TNBC; however, its toxic effects were more frequent than that of chemotherapy (NCT02574455). In this study, we discovered TROP2 target peptides with T-helper 1 (Th1) polarization and anticancer efficacy. We then evaluated the anti-tumor efficacy of these epitopes and possibility of co-administration with ADC in a TNBC murine model. Materials and Methods: Th1 peptides were identified using the Th-Vac® platform and the predictive binding affinity ranking that indicates potential immunogenicity points of interest for HLA class II. Human peripheral blood mononuclear cell (PBMC) Th1-specific polarization-induced activity and in vivo immunogenicity (Module 2b) were evaluated using flow cytometry and ELISpot analysis. The anti-tumor efficacy of the selected Th1 peptide was evaluated against MDA-MB-23 inoculated athymic Balb/c mice. Each peptide was administered intradermally once weekly for a total of four times at a concentration of 100 μg/head. Sacituzumab govitecan (0.81 mg/kg) was administered intravenously once weekly, for a total of two times. Results: Ten peptides with high affinity for HLA class II were selected, and three epitopes that induce differentiation of T cells secreting TROP2-specific IFN-γ were subsequently selected. These epitopes (p1, p3 and p6) showed tumor growth inhibition efficacy of 52.4%, 38.5%, and 57.2%, respectively, compared to the control (vehicle) group in the TNBC tumor-bearing mice. The cocktail vaccine (AST-07X), which combined these epitopes, was the most dominant at 65.4%. The anti-tumor efficacy of the combination group of the cocktail vaccine and ADC was 77.4% compared with the control group, showing a potent synergistic effect compared to the 46.1% anti-tumor efficacy of the ADC-mono group. Conclusion: AST-07X that induce TROP2-specific Th1 anticancer immune responses, showed sufficient anti-tumor efficacy; these effects were evident under immunodeficient conditions, such as those of TNBC tumor-bearing athymic mice. Synergy effects were also induced via combined ADC administration. We are currently conducting further research on humanized mice to address the limitations of the immunodeficient murine model. Citation Format: Jinho Kang, Hyo-Hyun Park, Jin Kyeong Choi, Seong-Yong Jang, Min-Ah Kim, Myeong-Kyu Park, Ashley Youngmin Kim, Eunkyo Joung, Hun Jung. The anti-tumor efficacy of Th1-specific TROP2 vaccine (AST-07X) in a triple-negative breast cancer murine model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6757.

Abstract 5733: Development of a topoisomerase 1 inhibitor platform technology for efficacious and well tolerated ADCs

Abstract Topoisomerase 1 (TOP1) inhibitors are a class of cytotoxic small molecules that have demonstrated effectiveness as therapeutic agents in cancer. However, the broad clinical application has been hindered by poor pharmacokinetic profiles and off-target toxicities. Antibody-drug conjugates (ADCs) enable the targeted delivery of cytotoxic payloads by specifically targeting cell-surface antigens expressed on cancers reducing systemic exposure and toxicity. TOP1-ADCs have received FDA approval for HER2- (trastuzumab-deruxtecan) and Trop2- (sacituzumab-govitecan) expressing solid tumors, demonstrating the promise for this drug class to improve the lives of patients. We have developed a novel drug-linker using a potent TOP1 inhibitor with desirable ADME properties, and a hydrophilic glycoside linker as a platform technology enabling ADCs with favorable physicochemical and biological properties. The TOP1 inhibitor payload was optimized for potency, with reduced P-glycoprotein efflux and enhanced permeability. The hydrophilicity of the linker facilitates the development of highly loaded ADCs (8 drugs/mAb) with high plasma stability, low aggregation, and pharmacokinetics similar to parental antibody. The resultant ADCs are potent and immunologically specific with activity in multidrug-resistant tumor models and bystander activity in heterogenous antigen models. Human cancer cell derived xenograft models demonstrated potent and specific ADC anti-tumor activity with several targets and indications. Improved activity was observed compared to corresponding govitecan- and deruxtecan-based ADCs. ADCs prepared from this drug-linker technology were well tolerated in rats after repeat administration of 60 mg/kg every 4 days for 4 doses. The excellent anti-tumor activity in several models and favorable safety profile demonstrates this platform TOP1 drug-linker technology has the potential for development as ADCs against many cancer targets. Citation Format: Ryan Lyski, Lauren Bou, Johann Sigurjonsson, David Meyer, Calvin Neace, David Ortiz, Katie Snead, Kaleb Smith, Steven Jin, Nicole Stevens, Julia Cochran, Kaveh Alizadeh, Narayana Yeddula, Erica McKinney, Adam Peterson, Lindsay Dotloe, Jessica Simmons, Christopher Carosino, Kim Emmerton, Nancy Everds, Scott Jeffrey, Peter Senter. Development of a topoisomerase 1 inhibitor platform technology for efficacious and well tolerated ADCs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5733.

Abstract 1910: Advancing therapeutic interventions for NUT carcinoma: Orchestrating the precision of CRISPR/Cas9-mediated NUTM1 suppression and synergistic ADC strategies

Abstract Purpose: NUT carcinoma (NC) is aggressive carcinoma defined by translocations involving the NUTM1 and frequent squamous differentiation. NUTM1 gene encodes a testicular nuclear protein (NUT), exclusively expressed in the testis. The fusion of NUTM1 leads to abnormal cell growth, resulting in the development of NC. This study aims to discover advanced approaches for inducing the death of cancer cells, specifically targeting those expressing NUT proteins. Methods: Spatial Transcriptome analysis and RNA sequencing were applied to formalin-fixed paraffin-embedded NUTM1 fusion-positive cancer tissues. Virus-like particles were used to introduce CRISPR/Cas9 into cells expressing the NUTM1 fusion oncoprotein. The inhibitory effect was confirmed through multiple in vitro assays. The effectiveness of Anti-Trophoblastic cell-surface antigen (TROP-2) Antibody-Drug Conjugate (ADC) was demonstrated in vivo and in vitro in cells with increased TROP2 expression subsequent to NUT suppression. Results: NCs revealed a relatively uniform pattern of gene expression, forming six unique groups. Notably, the NUT protein predominantly located in the inner regions of the tumor tissues. We employed CRISPR/Cas9 technology to specifically target cells harboring the NUTM1 fusion gene. The precise genetic editing was remarkably effective, achieving up to 90% success in the targeted area. This led to a notable decrease in both RNA and protein levels of NUT expression, effectively disrupting associated downstream pathways. The cell growth rate was reduced in several NC cell lines, and differentiation, accompanied by morphological changes, was observed in most edited cells. RNA sequencing analysis of these edited cells uncovered a substantial increase in expression of cytosolic molecules, with a marked increase in TACSTD2 expression. Interestingly, when we combined this genetic editing approach with a targeted therapy - the TROP2-ADC loaded with interferon-beta - the results were even more striking. Cells treated with this combination showed almost double the rate of growth inhibition compared to those receiving only a single form of treatment. Conclusion: This study provides valuable insights into identifying novel therapeutic targets and elucidating potential mechanisms by analyzing NUT cancer tissues using various assays. Our results support that CRISPR/Cas9-mediated targeting of NUTM1 could be a useful approach for NUT oncoprotein ablation, especially when used in combination with other therapies such as ADCs. Further studies are needed to investigate the efficacy of NUT inhibition in preclinical and clinical settings. the elimination of tumor cells facilitated by CRISPR/Cas9, along with additional tumor markers targeted by ADCs, holds potential for developing treatment strategies against incurable cancers driven by genetic alterations. Citation Format: Juyoung Choi, Hwa Lin Yi, Hee Geon Park, Misook Lee, Daesik Kim, Sung Youl Hong, Young Kee Shin, Yoon-la Choi. Advancing therapeutic interventions for NUT carcinoma: Orchestrating the precision of CRISPR/Cas9-mediated NUTM1 suppression and synergistic ADC strategies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1910.

Antibody-drug conjugates targeting HER2 for the treatment of urothelial carcinoma: potential therapies for HER2-positive urothelial carcinoma.

Urothelial carcinoma (UC) is a common cancer characterized by high morbidity and mortality rates. Despite advancements in treatment, challenges such as recurrence and low response rates persist. Antibody-drug conjugates (ADCs) have emerged as a promising therapeutic approach for various cancers, although their application in UC is currently limited. This review focuses on recent research regarding ADCs designed to treat UC by targeting human epidermal growth factor receptor 2 (HER2), a surface antigen expressed on tumor cells. ADCs comprise three main components: an antibody, a linker, and a cytotoxic payload. The antibody selectively binds to tumor cell surface antigens, facilitating targeted delivery of the cytotoxic drug, while linkers play a crucial role in ensuring stability and controlled release of the payload. Cleavable linkers release the drug within tumor cells, while non-cleavable linkers ensure stability during circulation. The cytotoxic payload exerts its antitumor effect by disrupting cellular pathways. HER2 is commonly overexpressed in UCs, making it a potential therapeutic target. Several ADCs targeting HER2 have been approved for cancer treatment, but their use in UC is still being tested. Numerous HER2 ADCs have demonstrated significant growth inhibition and induction of apoptosis in translational models of HER2-overexpressing bladder cancer. Ongoing clinical trials are assessing the efficacy and safety of ADCs targeting HER2 in UC, with the aim of determining tumor response and the potential of ADCs as a treatment option for UC patients. The development of effective therapies with improved response rates and long-term effectiveness is crucial for advanced and metastatic UC. ADCs targeting HER2 show promise in this regard and merit further investigation for UC treatment.

Sex-specific changes in protein expression of membrane transporters in the brain cortex of 5xFAD mouse model of Alzheimer's disease.

Membrane transporters playing an important role in the passage of drugs, metabolites and nutrients across the membranes of the brain cells have been shown to be involved in pathogenesis of Alzheimer's disease (AD). However, little is known about sex-specific changes in transporter protein expression at the brain in AD. Here, we investigated sex-specific alterations in protein expression of three ATP-binding cassette (ABC) and five solute carriers (SLC) transporters in the prefrontal cortex of a commonly used model of familial AD (FAD), 5xFAD mice. Sensitive liquid chromatography tandem mass spectrometry-based quantitative targeted absolute proteomic analysis was applied for absolute quantification of transporter protein expression. We compared the changes in transporter protein expressions in 7-month-old male and female 5xFAD mice versus sex-matched wild-type mice. The study revealed a significant sex-specific increase in protein expression of ABCC1 (p = 0.007) only in male 5xFAD mice as compared to sex-matched wild-type animals. In addition, the increased protein expression of glucose transporter 1 (p = 0.01), 4F2 cell-surface antigen heavy chain (p = 0.01) and long-chain fatty acid transport protein 1 (p = 0.02) were found only in female 5xFAD mice as compared to sex-matched wild-type animals. Finally, protein expression of alanine/serine/cysteine/threonine transporter 1 was upregulated in both male (p = 0.02) and female (p = 0.002) 5xFAD mice. The study provides important information about sex-specific changes in brain cortical transporter expression in 5xFAD mice, which will facilitate drug development of therapeutic strategies for AD targeting these transporters and drug delivery research.

Causal effects of immune cell surface antigens and functional outcome after ischemic stroke: a Mendelian randomization study.

While observational studies link immune cells with post-stroke functional outcome, the underlying immune mechanisms are not well understood. Immune cell surface antigens are actively involved in the biological behavior of immune cells, investigating immune cell surface antigens could deepen our comprehension of their role and biological processes in stroke recovery. Therefore, we aimed to investigate the immunological basis of stroke outcome by exploring the causal relationship between immune cell surface antigens and functional outcome after ischemic stroke in a Mendelian randomization study. Genetic variants related to immune cell surface antigens and post-stroke functional outcome were selected for two-sample Mendelian randomization (MR) analysis. 389 fluorescence intensities (MFIs) with surface antigens were included. Inverse variance weighted (IVW) modeling was used as the primary MR method to estimate the causal effect of exposure on the outcome, followed by several alternative methods and sensitivity analyses. Additional analysis of the association between immune cell surface antigens and risk of ischemic stroke for assessment of collider bias. We found that suggestive associations between CD20 on switched memory B cell (OR = 1.16, 95% CI: 1.01-1.34, p = 0.036) and PDL-1 on monocyte (OR = 1.32, 95% CI: 1.04-1.66, p = 0.022) and poor post-stroke functional outcome, whereas CD25 on CD39+ resting Treg (OR = 0.77, 95% CI: 0.62-0.96, p = 0.017) was suggestively associated with good post-stroke functional outcome. The elevated CD20 on switched memory B cell, PDL-1 on monocyte, and CD25 on CD39+ resting Treg may be novel biomarkers and potential causal factors influencing post-stroke functional outcome.

B-cell targeted therapies in autoimmune encephalitis: mechanisms, clinical applications, and therapeutic potential.

Autoimmune encephalitis (AE) broadly refers to inflammation of the brain parenchyma mediated by autoimmune mechanisms. In most patients with AE, autoantibodies against neuronal cell surface antigens are produced by B-cells and induce neuronal dysfunction through various mechanisms, ultimately leading to disease progression. In recent years, B-cell targeted therapies, including monoclonal antibody (mAb) therapy and chimeric antigen receptor T-cell (CAR-T) therapy, have been widely used in autoimmune diseases. These therapies decrease autoantibody levels in patients and have shown favorable results. This review summarizes the mechanisms underlying these two B-cell targeted therapies and discusses their clinical applications and therapeutic potential in AE. Our research provides clinicians with more treatment options for AE patients whose conventional treatments are not effective.

Challenges in the discovery of tumor-specific alternative splicing-derived cell-surface antigens in glioma

Despite advancements in cancer immunotherapy, solid tumors remain formidable challenges. In glioma, profound inter- and intra-tumoral heterogeneity of antigen landscape hampers therapeutic development. Therefore, it is critical to consider alternative sources to expand the repertoire of targetable (neo-)antigens and improve therapeutic outcomes. Accumulating evidence suggests that tumor-specific alternative splicing (AS) could be an untapped reservoir of antigens. In this study, we investigated tumor-specific AS events in glioma, focusing on those predicted to generate major histocompatibility complex (MHC)-presentation-independent, cell-surface antigens that could be targeted by antibodies and chimeric antigen receptor-T cells. We systematically analyzed bulk RNA-sequencing datasets comparing 429 tumor samples (from The Cancer Genome Atlas) and 9166 normal tissue samples (from the Genotype-Tissue Expression project), and identified 13 AS events in 7 genes predicted to be expressed in more than 10% of the patients, including PTPRZ1 and BCAN, which were corroborated by an external RNA-sequencing dataset. Subsequently, we validated our predictions and elucidated the complexity of the isoforms using full-length transcript amplicon sequencing on patient-derived glioblastoma cells. However, analyses of the RNA-sequencing datasets of spatially mapped and longitudinally collected clinical tumor samples unveiled remarkable spatiotemporal heterogeneity of the candidate AS events. Furthermore, proteomics analysis did not reveal any peptide spectra matching the putative antigens. Our investigation illustrated the diverse characteristics of the tumor-specific AS events and the challenges of antigen exploration due to their notable spatiotemporal heterogeneity and elusive nature at the protein levels. Redirecting future efforts toward intracellular, MHC-presented antigens could offer a more viable avenue.

Chikungunya virus infection disrupts MHC-I antigen presentation via nonstructural protein 2.

Infection by chikungunya virus (CHIKV), a mosquito-borne alphavirus, causes severe polyarthralgia and polymyalgia, which can last in some people for months to years. Chronic CHIKV disease signs and symptoms are associated with the persistence of viral nucleic acid and antigen in tissues. Like humans and nonhuman primates, CHIKV infection in mice results in the development of robust adaptive antiviral immune responses. Despite this, joint tissue fibroblasts survive CHIKV infection and can support persistent viral replication, suggesting that they escape immune surveillance. Here, using a recombinant CHIKV strain encoding the fluorescent protein VENUS with an embedded CD8+ T cell epitope, SIINFEKL, we observed a marked loss of both MHC class I (MHC-I) surface expression and antigen presentation by CHIKV-infected joint tissue fibroblasts. Both in vivo and ex vivo infected joint tissue fibroblasts displayed reduced cell surface levels of H2-Kb and H2-Db MHC-I proteins while maintaining similar levels of other cell surface proteins. Mutations within the methyl transferase-like domain of the CHIKV nonstructural protein 2 (nsP2) increased MHC-I cell surface expression and antigen presentation efficiency by CHIKV-infected cells. Moreover, expression of WT nsP2 alone, but not nsP2 with mutations in the methyltransferase-like domain, resulted in decreased MHC-I antigen presentation efficiency. MHC-I surface expression and antigen presentation was rescued by replacing VENUS-SIINFEKL with SIINFEKL tethered to β2-microglobulin in the CHIKV genome, which bypasses the requirement for peptide processing and TAP-mediated peptide transport into the endoplasmic reticulum. Collectively, this work suggests that CHIKV escapes the surveillance of antiviral CD8+ T cells, in part, by nsP2-mediated disruption of MHC-I antigen presentation.

Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment.

This study aims to evaluate the impact of asiaticoside (AC) on the viability and proliferation of dental pulp stem cells (DPSCs), considering the known negative effects of routinely used intracanal medicaments. This evaluation will be compared with the outcomes from using traditional intracanal medicaments, specifically triple antibiotic paste (TAP) and calcium hydroxide [Ca(OH)2]. The DPSCs were obtained from the third molars of an adult donor. The application of flow cytometry was employed to do a phenotypic analysis on DPSCs using CD90, CD73, CD105, CD34, CD14, and CD45 antibodies. The methylthiazol tetrazolium (MTT) assay was employed to assess cellular viability. The cells were treated with different concentrations of TAP and Ca(OH)2 (5, 2.5, 1, 0.5, and 0.25 mg/mL), along with AC (100, 50, 25, 12.5, and 6.25 µM). A cell proliferation rate was performed at 3, 5, and 7 days. The characterization of DPSCs was conducted by flow cytometry analysis, which verified the presence of mesenchymal cell surface antigen molecules (CD105, CD73, and CD90) and demonstrated the absence of hematopoietic markers (CD34, CD45, and CD14). Cells treated with concentrations over 0.5 mg/mL of TAP and Ca(OH)2 showed a notable reduction in cell viability in comparison to the untreated cells (p < 0.05). Additionally, the cells treated with different concentrations of AC 12.5, 6.25, 25, and 50 µM did not differ significantly from the untreated cells (p > 0.05). Nevertheless, cells treated with concentrations of 100 µM showed a significant reduction in viability compared to the untreated cells (p < 0.05). After a period of 7 days, it was noted that cells exposed to three different concentrations of AC (50, 25, and 12.5 µM) had a notable rise in cell density in comparison to TAP and Ca(OH)2 (p < 0.05). Furthermore, cells that were exposed to a concentration of 12.5 µM exhibited the highest cell density. The cellular viability of the AC-treated cells was superior to that of the TAP and Ca(OH)2-treated cells. Moreover, the AC with a concentration of 12.5 µM had the highest degree of proliferation. This study underscores the importance of evaluating alternative root canal medicaments and their effects on DPSCs' growth and vitality. The findings on AC, particularly its influence on the survival and proliferation of DPSCs, offer valuable insights for its probable use as an intracanal medication. This research contributes to the ongoing efforts to identify safer and more effective intracanal treatments, which are crucial for enhancing patient outcomes in endodontic procedures. How to cite this article: Alazemi MJ, Badawi MF, Elbeltagy MG, et al. Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment. J Contemp Dent Pract 2024;25(2):118-127.

Abstract P18: Splicing polymorphism rs12459419 modulates antibody-bound internalization of CD33 isoforms

Abstract P18: Splicing polymorphism rs12459419 modulates antibody-bound internalization of CD33 isoforms

Effects of therapeutic hypercapnia on the expression and function of γδT cells in transplanted lungs in rats.

To investigate the effect of therapeutic hypercapnia on the expression and function of gamma delta T (γδ T) cells during ischemia-reperfusion injury (IRI) after lung transplantation. We randomly divided male Wistar rats into three groups (n = 6 in each group), the control group (group N), the IRI group (group I), and the therapeutic hypercapnia group (group H). We then assessed pulmonary edema, neutrophil infiltration, wet-to-dry (W/D) weight ratio, and microscopic histopathology and separately measured the levels of γδT cell surface antigen (TCR) and Interleukin-17 (IL-17) using flow cytometry and enzyme-linked immunosorbent assays (ELISAs). The infiltration of neutrophils and the expression of TCR and IL-17 were significantly increased in the I group compared to the control, and the biopsy edema in group I was more severe. Arterial partial pressure of oxygen (PaO2) was decreased after reperfusion in group I compared with the control group. W/D weight ratio, neutrophil infiltration, and the expression of TCR and IL-17 decreased drastically in the H group compared to the I group. Our findings suggest that γδ T lymphocytes were directly involved in lung injury. In addition, therapeutic hypercapnia effectively reduced the expression of γδ T cells and IL-17, and this has the potential to become a treatment strategy for IRI and an intervention to improve lung function.

Sacituzumab Govitecan: A Review in Unresectable or Metastatic HR+/HER2- Breast Cancer.

Sacituzumab govitecan (TRODELVY®) is a first-in-class trophoblast cell-surface antigen 2 (Trop-2)-directed antibody and topoisomerase I inhibitor conjugate that is approved globally as monotherapy for the treatment of adults with unresectable locally advanced or metastatic, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-; defined as immunohistochemistry 0, 1+ or 2+ and in situ hybridization-negative) breast cancer who have received endocrine-based therapy and ≥2 additional systemic therapies in the advanced setting. In the phase III TROPiCS-02 trial, intravenous sacituzumab govitecan demonstrated statistically significant and clinically meaningful improvements in progression-free survival and overall survival compared with physician's choice of chemotherapy (capecitabine, eribulin, gemcitabine or vinorelbine) in adults with metastatic HR+/HER2- breast cancer. Sacituzumab govitecan had a generally manageable tolerability profile in these patients; the most common treatment-related grade ≥3 adverse events included neutropenia, diarrhoea, leukopenia, anaemia, fatigue and febrile neutropenia. Sacituzumab govitecan carries regulatory warnings for severe neutropenia and severe diarrhoea. Sacituzumab govitecan demonstrated an overall benefit in terms of health-related quality of life. Current evidence indicates that sacituzumab govitecan is an effective treatment option, with a generally manageable tolerability profile, for patients with pre-treated, unresectable locally advanced or metastatic HR+/HER2- breast cancer.

Final Results From the Randomized Phase III ASCENT Clinical Trial in Metastatic Triple-Negative Breast Cancer and Association of Outcomes by Human Epidermal Growth Factor Receptor 2 and Trophoblast Cell Surface Antigen 2 Expression.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Sacituzumab govitecan (SG), a first-in-class anti-trophoblast cell surface antigen 2 (Trop-2) antibody-drug conjugate, demonstrated superior efficacy over single-agent chemotherapy (treatment of physician's choice [TPC]) in patients with metastatic triple-negative breast cancer (mTNBC) in the international, multicenter, phase III ASCENT study.Patients were randomly assigned 1:1 to receive SG or TPC until unacceptable toxicity/progression. Final efficacy secondary end point analyses and post hoc analyses of outcomes stratified by Trop-2 expression and human epidermal growth factor receptor 2 status are reported. Updated safety analyses are provided.In this final analysis, SG (n = 267) improved median progression-free survival (PFS; 4.8 v 1.7 months; hazard ratio (HR), 0.41 [95% CI, 0.33 to 0.52]) and median overall survival (OS; 11.8 v 6.9 months; HR, 0.51 [95% CI, 0.42 to 0.63]) over TPC (n = 262). SG improved PFS over TPC in each Trop-2 expression quartile (n = 168); a trend was observed for improved OS across quartiles. Overall, SG had a manageable safety profile, with ≤5% of treatment-related discontinuations because of adverse events and no treatment-related deaths. The safety profile was consistent across all subgroups.These data confirm the clinical benefit of SG over chemotherapy, reinforcing SG as an effective treatment option in patients with mTNBC in the second line or later.

CD151 expression marks atrial- and ventricular- differentiation from human induced pluripotent stem cells

Current differentiation protocols for human induced pluripotent stem cells (hiPSCs) produce heterogeneous cardiomyocytes (CMs). Although chamber-specific CM selection using cell surface antigens enhances biomedical applications, a cell surface marker that accurately distinguishes between hiPSC-derived atrial CMs (ACMs) and ventricular CMs (VCMs) has not yet been identified. We have developed an approach for obtaining functional hiPSC-ACMs and -VCMs based on CD151 expression. For ACM differentiation, we found that ACMs are enriched in the CD151low population and that CD151 expression is correlated with the expression of Notch4 and its ligands. Furthermore, Notch signaling inhibition followed by selecting the CD151low population during atrial differentiation leads to the highly efficient generation of ACMs as evidenced by gene expression and electrophysiology. In contrast, for VCM differentiation, VCMs exhibiting a ventricular-related gene signature and uniform action potentials are enriched in the CD151high population. Our findings enable the production of high-quality ACMs and VCMs appropriate for hiPSC-derived chamber-specific disease models and other applications.

A pharmacovigilance study on antibody-drug conjugate (ADC)-related neurotoxicity based on the FDA adverse event reporting system (FAERS).

Background: Antibody-drug conjugates (ADCs) are a relatively new class of anticancer agents that use monoclonal antibodies to specifically recognize tumour cell surface antigens. However, off-target effects may lead to severe adverse events. This study evaluated the neurotoxicity of ADCs using the FDA Adverse Event Reporting System (FAERS) database. Research design and methods: Data were extracted from the FAERS database for 2004 Q1 to 2022 Q4. We analysed the clinical characteristics of ADC-related neurological adverse events (AEs). We used the reporting odds ratio (ROR) and proportional reporting ratio (PRR) for the disproportionality analysis to evaluate the potential association between AEs and ADCs. Results: A total of 562 cases of neurological AEs were attributed to ADCs. The median age was 65years old [(Min; Max) = 3; 92]. Neurotoxic signals were detected in patients receiving brentuximab vedotin, enfortumab vedotin, polatuzumab vedotin, trastuzumab emtansine, gemtuzumab ozogamicin, inotuzumab ozogamicin, and trastuzumab deruxtecan. The payloads of brentuximab vedotin, enfortumab vedotin, polatuzumab vedotin, and trastuzumab emtansine were microtubule polymerization inhibitors, which are more likely to develop neurotoxicity. We also found that brentuximab vedotin- and gemtuzumab ozogamicin-related neurological AEs were more likely to result in serious outcomes. The eight most common ADC-related nervous system AE signals were peripheral neuropathy [ROR (95% CI) = 16.98 (14.94-19.30), PRR (95% CI) = 16.0 (14.21-18.09)], cerebral haemorrhage [ROR (95% CI) = 9.45 (7.01-12.73), PRR (95% CI) = 9.32 (6.95-12.50)], peripheral sensory neuropathy [ROR (95% CI) = 47.87 (33.13-69.19), PRR (95% CI) = 47.43 (32.93-68.30)], polyneuropathy [ROR (95% CI) = 26.01 (18.61-36.33), PRR (95% CI) = 25.75 (18.50-35.86)], encephalopathy [ROR (95% CI) = 5.16 (3.32-8.01), PRR (95% CI) = 5.14 (3.32-7.96)], progressive multifocal leukoencephalopathy [ROR (95% CI) = 22.67 (14.05-36.58), PRR (95% CI) = 22.52 (14.01-36.21)], taste disorder [ROR (95% CI) = 26.09 (15.92-42.76), PRR (95% CI) = 25.78 (15.83-42.00)], and guillain barrier syndrome [ROR (95% CI) = 17.844 (10.11-31.51), PRR (95% CI) = 17.79 (10.09-31.35)]. The mortality rate appeared to be relatively high concomitantly with AEs in the central nervous system. Conclusion: ADCs may increase the risk of neurotoxicity in cancer patients, leading to serious mortality. With the widespread application of newly launched ADC drugs, combining the FAERS data with other data sources is crucial for monitoring the neurotoxicity of ADCs. Further studies on the potential mechanisms and preventive measures for ADC-related neurotoxicity are necessary.

Pericyte Microvesicles as Plasma Biomarkers Reflecting Brain Microvascular Signaling in Patients With Acute Ischemic Stroke.

Blood-based biomarkers have the potential to reflect cerebrovascular signaling after microvascular injury; yet, the detection of cell-specific signaling has proven challenging. Microvesicles retain parental cell surface antigens allowing detection of cell-specific signaling encoded in their cargo. In ischemic stroke, the progression of pathology involves changes in microvascular signaling whereby brain pericytes, perivascular cells wrapping the microcapillaries, are one of the early responders to the ischemic insult. Intercepting the pericyte signaling response peripherally by isolating pericyte-derived microvesicles may provide not only diagnostic information on microvascular injury but also enable monitoring of important pathophysiological mechanisms. Plasma samples were collected from patients with acute ischemic stroke (n=39) at 3 time points after stroke onset: 0 to 6 hours, 12 to 24 hours, and 2 to 6 days, and compared with controls (n=39). Pericyte-derived microvesicles were isolated based on cluster of differentiation 140b expression and quantified by flow cytometry. The protein content was evaluated using a proximity extension assay, and vascular signaling pathways were examined using molecular signature hallmarks and gene ontology. In this case-control study, patients with acute ischemic stroke showed significantly increased numbers of pericyte-derived microvesicles (median, stroke versus controls) at 12 to 24 hours (1554 versus 660 microvesicles/μL; P=0.0041) and 2 to 6 days after stroke (1346 versus 660 microvesicles/μL; P=0.0237). Their proteome revealed anti-inflammatory properties mediated via downregulation of Kirsten rat sarcoma virus and IL (interleukin)-6/JAK/STAT3 signaling at 0 to 6 hours, but proangiogenic as well as proinflammatory signals at 12 to 24 hours. Between 2 and 6 days, proteins were mainly associated with vascular remodeling as indicated by activation of Hedgehog signaling in addition to proangiogenic signals. We demonstrate that the plasma of patients with acute ischemic stroke reflects (1) an early and time-dependent increase of pericyte-derived microvesicles and (2) changes in the protein cargo of microvesicles over time indicating cell signaling specifically related to inflammation and vascular remodeling.

Candidate Biomarkers for Targeting in Type 1 Diabetes; A Bioinformatic Analysis of Pancreatic Cell Surface Antigens.

Type 1 diabetes (T1Ds) is an autoimmune disease in which the immune system invades and destroys insulin-producing cells. Nevertheless, at the time of diagnosis, about 30-40% of pancreatic beta cells are healthy and capable of producing insulin. Bi-specific antibodies, chimeric antigen receptor regulatory T cells (CAR-Treg cells), and labeled antibodies could be a new emerging option for the treatment or diagnosis of type I diabetic patients. The aim of the study is to choose appropriate cell surface antigens in the pancreas tissue for generating an antibody for type I diabetic patients. In this bioinformatics study, we extracted pancreas-specific proteins from two large databases; the Human Protein Atlas (HPA) and Genotype-Tissue Expression (GTEx) Portal. Pancreatic-enriched genes were chosen and narrowed down by Protter software for the investigation of accessible extracellular domains. The immunohistochemistry (IHC) data of the protein atlas database were used to evaluate the protein expression of selected antigens. We explored the function of candidate antigens by using the GeneCards database to evaluate the potential dysfunction or activation/hyperactivation of antigens after antibody binding. The results showed 429 genes are highly expressed in the pancreas tissue. Also, eighteen genes encoded plasma membrane proteins that have high expression in the microarray (GEO) dataset. Our results introduced four structural proteins, including NPHS1, KIRREL2, GP2, and CUZD1, among all seventeen candidate proteins. The presented antigens can potentially be used to produce specific pancreatic antibodies that guide CARTreg, bi-specific, or labeling molecules to the pancreas for treatment, detection, or other molecular targeted therapy scopes for type I diabetes.

Plasmodium falciparum Glutamic Acid-Rich Protein-Independent Polyclonal Antibodies Inhibit Malaria Parasite Growth in Human Erythrocytes.

Plasmodium falciparum glutamic acid-rich protein (PfGARP) is a recently characterized cell surface antigen encoded by Plasmodium falciparum, the causative agent of severe human malaria pathophysiology. Previously, we reported that the human erythrocyte band 3 (SLC4A1) serves as a host receptor for PfGARP. Antibodies against PfGARP did not affect parasite invasion and growth. We surmised that PfGARP may play a role in the rosetting and adhesion of malaria. Another study reported that antibodies targeting PfGARP exhibit potent inhibition of parasite growth. This inhibition occurred without the presence of any immune or complement components, suggesting the activation of an inherent density-dependent regulatory system. Here, we used polyclonal antibodies against PfGARP and a monoclonal antibody mAb7899 to demonstrate that anti-PfGARP polyclonal antibodies, but not mAb7899, exerted potent inhibition of parasite growth in infected erythrocytes independent of PfGARP. These findings suggest that an unknown malaria protein(s) is the target of growth arrest by polyclonal antibodies raised against PfGARP.

Postnatal development of mouse spermatogonial stem cells as determined by immunophenotype, regenerative capacity, and long-term culture-initiating ability: a model for practical applications

Spermatogonial stem cells (SSCs) are the foundation of life-long spermatogenesis. While SSC research has advanced greatly over the past two decades, characterization of SSCs during postnatal development has not been well documented. Using the mouse as a model, in this study, we defined the immunophenotypic profiles of testis cells during the course of postnatal development using multi-parameter flow cytometry with up to five cell-surface antigens. We found that the profiles progress over time in a manner specific to developmental stages. We then isolated multiple cell fractions at different developmental stages using fluorescent-activated cell sorting (FACS) and identified specific cell populations with prominent capacities to regenerate spermatogenesis upon transplantation and to initiate long-term SSC culture. The data indicated that the cell fraction with the highest level of regeneration capacity exhibited the most prominent potential to initiate SSC culture, regardless of age. Interestingly, refinement of cell fractionation using GFRA1 and KIT did not lead to further enrichment of regenerative and culture-initiating stem cells, suggesting that when a high degree of SSC enrichment is achieved, standard markers of SSC self-renewal or commitment may lose their effectiveness to distinguish cells at the stem cell state from committed progenitors. This study provides a significant information resource for future studies and practical applications of mammalian SSCs.